DTC 05: Brake Switch
WARNING: This page is about a different car, the 2002 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
Perform DTC 31. See DTC 31: BRAKE SWITCH CIRCUIT . If DTC 31 checks out okay, and DTC 05 is still indicated in condition detection mode of on-board diagnostics, replace cruise control module. See CRUISE ACTUATOR under REMOVAL & INSTALLATION.